Fiber-twist-spinning

ABSTRACT

An open-end spinning system characterized by laying straightened fibers next to each other onto an endless member and moving these deposited fibers in a generally perpendicular direction to the fiber orientation into a twisting zone where they are twisted and compacted into a yarn.

TECHNICAL FIELD

This invention relates to an apparatus and method for high-speed spinning of staple fibers into a yarn. More particularly, it is spinning yarn according to what is commonly known as an “open-end” spinning method.

BACKGROUND

High-speed spinning methods, also called “open-end” spinning methods have been known for many years. In general, they assemble a yarn from staple fibers without rotating the take-up package as is the case with the long established ring spinning. A major obstacles preventing full acceptance of these open-end spinning systems are the lack of even fiber alignment in the yarn, not being able to process a broad range of materials, fiber length and yarn size. An additional technological problem with rotor spinning is the limitation of production speed, caused by the centrifugal force of the rotating yarn end in the rotor.

The invention disclosed in this application applies to a new method of “open-end” spinning which presents well oriented fibers to the twisting location and assembles them under selectable tension onto the yarn end with minimal energy requirements. Its production speed is not affected by the strength and/or length of the individual fiber and there is no excess stress applied to the formed yarn.

SUMMARY OF THE INVENTION

Therefore, it is a principal purpose of the present invention to provide a quality yarn at high-speed by aligning the individual fibers before twisting them in stretched form onto the yarn end.

It is another object of the invention to produce a yarn at extremely high speed by twisting the yarn end around its axis and rotate the fibers around the same axis before being attached to the yarn end whereby the radius of rotation is very small.

It is another object of the invention to be able to select a desired withdraw tension of the yarn out of the twisting zone in order to further align the fibers and to stretch them in uniform manner which results in even load sharing of all fibers when the yarn is under stress.

It is a further target of the invention to hook fibers onto hook wires and have this hooked portion of the fiber trailing in the spinning process in order to pull out these hooks when the twisted yarn is pulled out of the twisting zone.

It is an object of this invention to first separate individual fibers from a fiber bundle. Next, to align these fibers parallel to each other. Then to move the individual fibers perpendicular to their alignment to the twisting zone. To rotate these fibers around the axis of a yarn end and bring their leading end in contact with the none-rotating yarn end thus adding length to the yarn end and withdrawing the yarn simultaneously.

According to one preferred embodiment of the invention, the parallel laying of stretched fibers is accomplished by pulling individual fibers from a fiber bundle by a combing roll. These individual fibers are then caught on hooks of an endless cross belt which runs in close proximity and perpendicularly to the tangential motion of the combing roll.

Another preferred embodiment uses a cross drum in place of a cross belt. This cross drum is equipped on it's periphery with hooks to capture the individual fibers. The axis of the cross drum is in general perpendicular direction to the axis of the combing roll.

It is also an object of the invention to remove the individual fibers from the cross belt or the cross drum, to capture them between a twist-belt and another stationary or moving member and feed them individually to the twisting zone. The high friction of the twist-belt overcomes possible drag of the other holding member.

It is an object of the invention to twist the yarn end and the individual fibers with the assistance of a needle which determines the precise twist in the yarn.

Another object of the invention is to be very flexible in the capability to spin fibers of various staple lengths at the same time or to be able to switch from short to long fibers without major machinery changes and visa versa.

BRIEF DESCRIPTION OF THE DRAWINGS

Some of the objects of the invention have been set forth above. Other objects and advantages of the invention will appear as the description of the invention proceeds when taken in conjunction with the following drawings, in which:

FIG. 1 is a perspective view of the spinning system according to one preferred embodiment of the invention;

FIG. 2 gives a frontal view of the spinning system, viewing it against the withdrawn yarn.

FIG. 3 is a left side view of the tension controller with the exiting yarn strand leaving to the right;

FIG. 4 is a left side view of the tension controller with the exiting yarn strand leaving to the right. The twist-belt has been removed to show the stripping blades and the twisting needle;

FIG. 5 is a frontal view of the spinning system according to one preferred embodiment of the invention with the takeoff rollers, the feed roll and the pressure shoe removed;

FIG. 6 shows the spinning system in a perspective view and showing the direction of drive of the system elements shown by arrows;

FIG. 7 is an exploded perspective view showing the parts of the spinning system more clearly;

FIG. 8 is a cross-section through the cross-belt with the hooked wires on the left and the straight wires on the right side.

FIG. 9 is a schematic diagram of the process, showing its process steps in view of the staple fibers;

FIG. 10 is a perspective view of a modification of the spinning system with a cross-drum taking the place of the cross-belt;

FIG. 11 shows how an individual fiber is hooked on a hooked wire of the cross-belt.

FIG. 12 is an enlarged front view of the area around the twisting needle.

FIG. 13 is a cross section through the cross-belt with a belt cover over the hooked and the straight wires.

FIG. 14 shows in perspective view a variation of the spinning system incorporating a core yarn into the center of the yarn strand.

FIG. 15 is a perspective view of the spinning arrangement where the twisting needle is slanted in view of the arriving fibers.

DESCRIPTION OF THE PREFERRED EMBODIMENT AND BEST MODE

Referring now specifically to the drawings, a spinning system is broadly illustrated in FIG. 1 in a perspective view. It shows a rotating feed roll 6 and a pressure shoe 7 for feeding a fiber bundle 16 (not shown) to a rotating combing roll 5. The combing roll 5 separates the individual fibers 20 (not shown) and lays them across the cross-belt 1. The cross-belt 1 is driven by the right belt-pulley 2 and the left belt-pulley 3. Stripping blades 10 (partially hidden) serve to strip the fibers 20 (not shown) from the cross-belt 1 and present them to the twist-belt 8, the twisting roll 11 and the twisting needle 12. The twist-belt 8 is driven by the twist-belt pulley 9. The bottom takeoff roller 13 and the top takeoff roller 14 pull the spun yarn 15 out from the spinning zone.

FIG. 2 shows the same arrangement in frontal view. It also shows how the belt guide 4 guides the lower portion of the cross-belt 1 into close proximity of the combing roll 5.

FIG. 3 portrays the spinning unit in a side view. The fiber bundle 16 enters the spinning unit between the feed roll 6 and the pressure shoe 7 and the spun yarn 15 leaves it by being pulled out from the spinning unit by the bottom takeoff roller 13 and the top takeoff roller 14.

FIG. 4 shows the unit from the same side as FIG. 3 but the twist-belt 8 and the twist-belt pulley 9 are left off to show more clearly how the stripping blades 10 reach between the rows of hooked wires 17 and the straight wires 18 to remove the fibers 20 (not shown) from the cross-belt 1.

Referring now to FIG. 5, some parts are left off in this frontal view to show more clearly how the cross-belt 1 is in close proximity of the combing roll 5 and how the stripping blades 10 reach close to the cross-belt 1 to strip the fibers 20 (not shown) from the cross-belt 1. Also shown is the twist-belt 8 hugging the stripping blades 10, the twisting roll 11 and the twisting needle 12 for positive transport of the fibers 20 (not shown) to the twisting needle 12 to be spun into a yarn 15 (not shown). It also should be noted that the sides of the stripping blades 10, which face the twist-belt 8 are smoothly polished for smooth gliding of the stripped fibers 20 (not shown).

FIG. 6 shows the unit in a perspective view from the front-right side. The motions of the moving members are indicated by arrows. The stripping blades are also more visible than in FIG. 1.

The described mechanical parts can be seen in the exploded view in FIG. 7.

Referring to FIG. 8 it is a cross-sectional view through the cross-belt 1. On it are mounted the hooked wires 17 on the left side and the straight wires 18 to the right from them. The fibers 20 (not shown) are moving from the left to the right by the combing roll 5 (not shown).

The diagram in FIG. 9 is a schematic picture of the process of this spinning system. The sliver, consisting of a bundle of fibers, is first pulled apart. This separates the fibers and orients them horizontally. These individual fibers are then placed parallel to each other and moved in a latter like manner vertically upwards. When these individual fibers reach the spinning zone they are moved into a rotational mode around the yarn end. This action twists the individual fibers around the yarn end and elongates the yarn as it is pulled in horizontal direction to the right.

A modification of the spinning system is shown in FIG. 10. The cross-belt 1 is replaced with a cross-drum 19. Beside this variation, it still employs the same spinning elements as in the previously explained method. As a further variation, the twisting roll 11 has been omitted. In this case the fibers 20 (not shown) are twisted between the twist-belt 8 and the stripping blades 10 around the twisting needle 12.

In the partial perspective view in FIG. 11 a fiber 20 is shown hooked around a hocked wire 17 and laid between the straight wires 18.

FIG. 12 is a partial view of FIG. 5 and shows the twisting zone 21 in enlarged view. Also indicated by arrows are the directions of the surface movements of the twisting members, the twist-belt 8 twisting roll 11 and the twisting needle 12. It is understood that the individual fibers 20 are arriving in the twisting zone generally parallel to the twisting axis of the twisting needle 12. It may however be at times of advantage to have the leading end of the fiber 20, the end pointing in the direction towards the observer, arrive before the trailing end or visa versa. Another variation is to twist the fibers into a yarn 15 without a twisting needle 12. This can be easily envisioned when the surface friction of twisting roll 11 is similar to the one of the twisting belt. As soon as the fibers 20 leave the stripping blades 10, the fibers are immediately twisted as they would be between the index finger and the thumb. Also shown in FIG. 12 is the nose pin 26. The nose pin 26 with the twist-belt 8 is pressing against the twisting fibers 20. As more pressure is exerted, the higher is the resistance of the yarn 15 to be pulled out of the twisting zone 21. The higher the pullout force, the more the fibers are stretched and aligned for improved yarn strength.

FIG. 13 it is a cross-sectional view through the cross-belt 1. It has some modification to the cross-belt 1 in FIG. 8. On it are mounted the hooked wires 17 on the left side and the straight wires 18 to the right. A fiber 20 is shown caught by a hooked wire 17. Between the rows of hooked wires 17 and straight wires 18 are stripper grooves 23 which provide some extra space for the stripping blades 10 (not shown). The cross-belt 1 also is provided with extra air porosity 22 which will allow air to pass through to facilitate the holding (with vacuum) as well as the removal (with air pressure) of the fibers 20. The stationary belt cover 24 is shown with optional cover ribs 25 to hold the fibers 20 firmly aligned between the hooked wires 17 and straight wires 18.

In FIG. 14 the twisting needle 12 contains a core-yarn hole 29 through its center. This allows to feed a core-yarn 30 to the twisting zone where the staple fibers 20 are wrapped around it for a variation of the spun yarn 15. The twisting needle 12 is mounted in two needle bearing 27 and is driven by a drive belt (not shown) over the needle pulley 28.

In FIG. 15 the twisting needle 12 is slanted in relation to the arriving fibers 20. This allows the twisting action to grab first the fiber tail 32 which causes the fibers 20 to be pulled from the hooked wire 17. This action will straighten out the fiber hook 31.

NUMBERING

-   cross-belt 1 -   right belt-pulley 2 -   left belt-pulley 3 -   belt guide 4 -   combing roll 5 -   feed roll 6 -   pressure shoe 7 -   twist-belt 8 -   twist-belt pulley 9 -   stripping blades 10 -   twisting roll 11 -   twisting needle 12 -   bottom takeoff roller 13 -   top takeoff roller 14 -   yarn 15 -   fiber bundle 16 -   hooked wire 17 -   straight wire 18 -   cross-drum 19 -   fiber 20 -   twisting zone 21 -   air porosity 22 -   stripper groove 23 -   belt cover 24 -   cover rib 25 -   nose pin 26 -   needle bearing 27 -   needle pulley 28 -   core-yarn hole 29 -   core-yarn 30 -   fiber hook 31 -   fiber tail 32 

1. Apparatus for twisting staple fibers into a yarn comprising: (a) a mechanism to separate individual fibers; (b) a mechanism to pull said individual fibers straight; (c) a continuous surface onto which said individual fibers are deposited parallel to each other; (d) moving said continuous surface with the deposited fibers in a direction which is generally at a right angle to the fiber orientation; (e) a twisting position where the row of parallel fibers are rolled up around an axis which is substantially parallel to the fiber orientation; (f) a yarn withdrawal means to continuously pulling rolled up fibers in axial direction.
 2. Apparatus according to claim 1 whereby the rolling together of the parallel fibers is accomplished by means of a rotating needle.
 3. Apparatus according to claim 1 whereby the rolling together of the parallel fibers is accomplished by means of counter rotating surfaces.
 4. Apparatus according to claim 1 whereby the rolling together of the parallel fibers is assisted by means of counter rotating surfaces around a rotating twisting needle.
 5. Apparatus according to claims 2 and 3 whereby the surfaces of the rolling members are pressed together with a selectable force.
 6. Apparatus according to claim 1 whereby the parallel fibers are caught by rows of wire hooks mounted on said continuous surface.
 7. Apparatus according to claim 6 comprising stripping blades located between the rows of wire hooks to assist in releasing the parallel fibers from the wire hooks.
 8. Apparatus according to claim 1 whereas said continuous surface is air permeable to allow air flow through said continuous surface to assist in the control of the parallel fibers.
 9. Apparatus according to claim 2 wherein the said rotating needle is hollow in order to place a core yarn into the center of the spun yarn.
 10. A method of twisting staple fibers together into a yarn comprising the steps of: (a) arranging individual staple fibers parallel to each other; (b) moving these fibers in a direction which is generally at a right angle to the fiber orientation; (c) twisting these fibers around an axis which is substantially parallel to the fiber orientation; (d) continuously pulling rolled up fibers in axial direction.
 11. A method of spinning staple fibers into a yarn according to claim 10 comprising the step of catching the tail of hooked fibers first in order to pull out trailing fiber hooks.
 12. A method of spinning staple fibers into a yarn according to claim 10 comprising the step of applying pressure to the rolling-up means in order to control the withdrawal tension while being pulled out of the twisting zone. 